A. Field of the Invention
This invention relates generally to the field of weapon systems and more particularly to a counter counting the number of rounds fired by a gun. The rounds counter is positioned remote from the gun. The rounds counter is particularly useful for gun mounts adapted to receive and fire a variety of different guns.
B. Description of Related Art
A remotely operated weapon station, such as the RAVEN™ stabilized remote weapons station produced by Recon Optical, Inc. is described in U.S. Pat. No. 6,769,347, the content of which is incorporated by reference herein. Other prior art of interest in the area of remotely operated weapon systems includes U.S. Pat. No. 5,949,015, the content of which is incorporated by reference herein.
These patents are directed to a weapon station that provides the capability to mount, remotely aim, and remotely fire a suite of crew served weapons. The weapon station is usually operated from inside an armored vehicle to which the weapon station is attached, and may also provide a capability for manual, local operation of the gun, e.g., in the event of a power failure. The weapon station is capable of mounting on a variety of vehicles, such as trucks, armored personnel carriers, high mobility multi-purpose vehicles commonly known as HUMVEEs, and military and police watercraft. The weapon station is powered by the host vehicle system power. The weapon mount may optionally be stabilized to remove vehicle motion from the weapon aimpoint. The weapon station consists of a mount having azimuth and elevation drives, weapon interface, viewing and sighting unit, remote control and display unit, and electronics support unit with fire control processor. Some weapon stations such as the Recon Optical RAVEN™ may offer additional features including optional weapon cradles, weapon remote firing capability, weapon remote charging capability, and an ammunition/magazine feed system.
Remote weapon stations rely on associated ammunition containers mounted on or near the weapon mount to supply the weapon used with rounds of ammunition. Since the weapon station is operated remotely from a control and display unit, the gunner/operator is not located near the weapon or the associated ammunition container. Therefore, the amount of ammunition remaining in the container after weapon firing sequences is not directly observable by the gunner/operator.
A means of having the system count the number of rounds fired and more importantly, the number of rounds remaining in the ammunition container, is important to the gunner-operator and a key performance parameter of a remote weapon station. Ammunition rounds counting mechanisms currently used in association with remote weapon stations typically allow the operator to enter the number of rounds loaded into the ammunition container, are able to count down from the total number of rounds loaded/entered, and display the number of rounds remaining for weapon firing.
Prior art references related to devices for detecting the firing of rounds from a gun in include the following references: Yerazunis et al., U.S. Pat. No. 7,158,167; Johnson et al., U.S. Pat. Nos. 7,143,644 and 7,100,437; Wright, Sr. et al., U.S. Pat. No. 5,799,432; Brinkley et al., U.S. Pat. No. 5,566,486; Brennan, U.S. Pat. No. 5,033,217; Hartcock, U.S. Pat. No. 5,303,495 and Sayre, U.S. Pat. No. 5,406,730. These references disclose the use of a variety of different technologies to detect the firing of a round, including recoil and sound transducers, proximity sensors, Hall-effect sensors and accelerometers. The sensor is typically mounted to the barrel of the gun (as in the Johnson et al. '644 patent) or elsewhere on the gun itself, e.g., in the handgrip.
With weapon mounts that are configured to fire a variety of different guns, one prior art approach to rounds counting is to provide each gun with its own rounds counters, the rounds counter mounted to the gun as in the above prior art. Some rounds counting mechanisms of the present art employ a slide switch which is activated by the action of the weapon bolt or round activating/loading/ejecting mechanism to record the weapon firing event by switch closure. Other rounds counters utilize an inductive proximity sensor that senses the presence of a metal brought within 2 mm of the active surface of the sensor, such as the movement of a weapon bolt or round activating/loading ejecting mechanism into the vicinity of the proximity of the sensor. Therefore, the location of the proximity sensor may be different for each weapon type used. For example, the M2 50 cal. machine gun locates the proximity sensor so the weapon bolt passes its active surface as it recoils. This implementation results in two events recorded for each shot fired. Other smaller caliber machine guns place the sensor near the feed port to again sense the bolt action. This can result in two or four events per cycle. A Mk19 grenade machine gun places the sensor in the feed mechanism to sense the front of the projectile, resulting in 1 event per round. In all the above cases, the rounds counting sensing mechanisms are located on the weapon or at the location of the weapon.
The difference in output signals resulting from the use of a proximity sensor with various weapons requires additional hardware and or software to be incorporated within the weapon system. Clearly, this is a disadvantage. For example, in one prior art gun, the proximity sensing scheme is made viable by using software to read the output of the proximity sensor 4000 times per second while the weapon trigger is active. The software therefore further qualifies the output by allowing only one count per given time period due to the multiple events per round. With other weapons, a completely different rounds counter arrangement is required. In order to accommodate all the possible rounds counters arrangements, each of which tends to be unique to a particular gun, more complex processing software and hardware is required. When additional gun capabilities are added to the gun mount, still further complexities arise. In short, the present situation is unsatisfactory in at least the following respects: 1) There is a high cost due to many parts needed to produce separate assemblies for each different weapon which is to be mounted to the mount (four in several current systems). 2) There is a need to measure and adjust each switch in order to count the rounds correctly. The adjustment could need to be checked and re-adjusted over the life of the unit. A separate adjustment tool is needed for each rounds counter. 3) Four different rounds counter assemblies are required to accommodate the four different weapons. 4) Multiple cables are needed to route data from each rounds counter assembly, mounted at the weapon, to the electronics unit for the weapon mount.
This invention provides for a common, single rounds counter arrangement that provides a count of the number of rounds that are fired by any gun that may be mounted to the weapon mount. The rounds counter achieves this goal because it is not physically attached to or part of the gun per se, or its ammunition feed supply, as in the prior art, but rather is mounted in a remote location, thereby overcoming the above-described problems and complexities. It has the at least the following advantages: 1) It is much cheaper to produce. 2) No adjustments are needed, and it does not need mechanical adjustment tools. 3) It is easily mounted in the weapon mount (e.g., in the pedestal of the mount) and not to each specific weapon. It is therefore gun mount specific, instead of weapon specific. 4) It has no moving parts, and has much less chance of problems in the field than current devices. 5) The design is reliable, and at least from a mechanical aspect, a more reliable way of rounds counting.